Human Chorionic Gonadotropin (hCG, choriogonadotropin), a hormone normally secreted by the placenta during pregnancy, has been shown to be present in the blood of 7-39% of patients with a wide variety of cancers, but not detectable in the blood of non-pregnant controls. The purpose of the present proposal is to increase the sensitivity of the present methods for measuring hCG, in order to enhance the usefulness of this substance for the immunodiagnosis of early cancer and for following the effects of therapy directed towards the neoplasms producing hCG ectopically. The sensitivity will be increased by adsorbing the hCG present in a 5-10 ml sample of blood to Concanavalin A and eluting it with 0,2 M methyl gamma-D-glucopyranoside, followed by dialysis, lyophilization, resuspension in a small volume of buffer, and measurement in the hCG-beta subunit radioimmunoassay. The specificity of the modified beta-hCG assay will be checked by similar treatment of blood obtained from post-menopausal patients. The immunologic, biologic and physical properties of the different molecular forms of hCG (isohormones and subunits) produced by these tumors will be studied since there is preliminary evidence that neoplasms which are responsive to therapy may have a different hCG secretion profile than those that are less responsive to treatment. Patients whose tumors produce hCG or its subunits will be compared to those whose tumors do not in regard to clinical presentation, duration of disease, stage and extent of disease, age, sex, race, tumor histology and grade, response to therapy, known areas of metastasis and survival.